[RFC PATCH v1 4/5] perf annotate: Wire up ARM64 data type profiling infrastructure

[Shuai Xue]

Add ARM64 support to the core dispatch and initialization points:

1. annotate_get_insn_location(): Add an arm64 branch alongside the
   existing powerpc branch to call get_arm64_regs() for extracting
   register numbers and memory offsets from raw instructions.

2. arch_supports_insn_tracking(): Include arm64 so that
   find_data_type_block() can perform instruction-level type state
   tracking on ARM64.

3. init_type_state(): Add arm64 branch to set caller-saved registers
   (x0-x18 per AAPCS64) and stack register (SP, DWARF reg 31).
   Without this, stack_reg defaults to 0 (x0) after memset, causing
   x0-based memory accesses to be misidentified as stack accesses.

Signed-off-by: Shuai Xue <xueshuai@xxxxxxxxxxxxxxxxx>
---
 tools/perf/util/annotate-data.c | 18 +++++++++++++++++-
 tools/perf/util/annotate.c      | 12 ++++++++----
 2 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/tools/perf/util/annotate-data.c b/tools/perf/util/annotate-data.c
index 1eff0a27237d..c04ad66ff077 100644
--- a/tools/perf/util/annotate-data.c
+++ b/tools/perf/util/annotate-data.c
@@ -29,6 +29,11 @@
 /* register number of the stack pointer */
 #define X86_REG_SP 7
 
+/* ARM64 DWARF register numbers: x0-x30=0-30, SP=31 */
+#define ARM64_REG_SP 31
+#define ARM64_REG_LR 30
+#define ARM64_REG_FP 29
+
 static void delete_var_types(struct die_var_type *var_types);
 
 #define pr_debug_dtp(fmt, ...)					\
@@ -178,6 +183,16 @@ static void init_type_state(struct type_state *state, const struct arch *arch)
 		state->ret_reg = 0;
 		state->stack_reg = X86_REG_SP;
 	}
+
+	if (arch__is_arm64(arch)) {
+		int i;
+
+		/* ARM64 ABI: x0-x18 are caller-saved */
+		for (i = 0; i <= 18; i++)
+			state->regs[i].caller_saved = true;
+		state->ret_reg = 0;
+		state->stack_reg = ARM64_REG_SP;
+	}
 }
 
 static void exit_type_state(struct type_state *state)
@@ -1421,7 +1436,8 @@ static enum type_match_result find_data_type_insn(struct data_loc_info *dloc,
 
 static int arch_supports_insn_tracking(struct data_loc_info *dloc)
 {
-	if ((arch__is_x86(dloc->arch)) || (arch__is_powerpc(dloc->arch)))
+	if ((arch__is_x86(dloc->arch)) || (arch__is_powerpc(dloc->arch)) ||
+	    (arch__is_arm64(dloc->arch)))
 		return 1;
 	return 0;
 }
diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index e745f3034a0e..bd734826538d 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -2574,19 +2574,23 @@ int annotate_get_insn_location(const struct arch *arch, struct disasm_line *dl,
 		op_loc->reg2 = -1;
 
 		if (insn_str == NULL) {
-			if (!arch__is_powerpc(arch))
+			if (!arch__is_powerpc(arch) && !arch__is_arm64(arch))
 				continue;
 		}
 
 		/*
-		 * For powerpc, call get_powerpc_regs function which extracts the
-		 * required fields for op_loc, ie reg1, reg2, offset from the
-		 * raw instruction.
+		 * For powerpc and arm64, call arch-specific functions to
+		 * extract the required fields for op_loc (reg1, reg2, offset)
+		 * from the raw instruction.
 		 */
 		if (arch__is_powerpc(arch)) {
 			op_loc->mem_ref = mem_ref;
 			op_loc->multi_regs = multi_regs;
 			get_powerpc_regs(dl->raw.raw_insn, !i, op_loc);
+		} else if (arch__is_arm64(arch)) {
+			op_loc->mem_ref = mem_ref;
+			op_loc->multi_regs = multi_regs;
+			get_arm64_regs(dl->raw.raw_insn, !i, op_loc);
 		} else if (strchr(insn_str, arch->objdump.memory_ref_char)) {
 			op_loc->mem_ref = true;
 			op_loc->multi_regs = multi_regs;
-- 
2.51.2.612.gdc70283dfc